1. Field of the Invention
The present invention relates to a junction structure and a junction method of conductive projection used for making electrical and mechanical connection when mounting, for example, semiconductor parts on a wiring board, such as a mother board. More particularly, the present invention is related to a junction structure of conductive projection, which is joined to a planarized surface having no steps by surrounding its root portion with a resin material in a ring form to have high junction strength, and to a junction method of the conductive projection.
2. Description of Related Art
In recent years, as electronic apparatuses are being further miniaturized and sophisticated, there are increasing demands for semiconductor parts to be mounted that should be more sophisticated and be even thinner, so that the semiconductor parts tend to have more and more pins. For meeting the demands, when rearrangement of chip electrode portions on an interposer is conducted without changing the wiring rule, the number of layers in the interposer is increased, causing a problem of an increase in the thickness of a package. Therefore, an interposer at a high wiring density which meets the demands of the increase of pins without sacrificing reduction of the thickness of the package is desired.
The increase of pins causes a bare chip to be larger, thus increasing the size of a package having the bare chip mounted. In accordance with this tendency, higher junction reliability is required in the junction between the package and the mother board.
In view of the above, for example, Patent document 1 has proposed a structure in which the root portion of the conductive projection joined onto an interposer is surrounded by a resin material to reinforce there.
[Patent Document 1]
Japanese Patent No. 2842361